She is best known for her lead role in the 2012 film Louise Wimmer, for which she was nominated for the Cesar Award for best actress.

Her early roles were in comedies by Georges Feydeau and adaptations of Rainer Werner Fassbinder.

[citation needed] In 2014, during the municipal elections, Masiero ran on the Left Front slate in Roubaix.

[2] She supported François Ruffin, for La France insoumise during the 2017 French legislative election.

[3] At the 2021 César Awards, Masiero stripped naked in protest against the French government's plan of COVID-19 restrictions.